Research On Oxygen Concentration Sensor And Carboniazation Process For Bamboo And Wood

Based on the ionic conductivity at high temperature and the mechanism of oxygenconcentration cell for zirconia, the seal connection between solid electrolyte and casing pipe,theinsulting properties of the sealing materials and their effects on output voltage of oxygen sensorare analyzed. With phosphate and copper oxide adhesive as the sealing material, the innerelectrode fuses, made of0Cr25Ni20heat-resistant steel, are adhered on the solid electrolyte withconductive adhesive made of platinum powder and high clay. And the outer electrode, made of0Cr25Ni20heat-resistant steel, is pressed on the solid electrolyte with spring.The heating chamberand temperature control system of the sensor are developed, which is not restricted bycarbonization temperature and oxygen concentration in furnace. Finally, the U-tube Yttriastabilized zirconia oxygen sensor with heating chamber is produced.With the oxygen sensor, carboniazation process for wood, bamboo, and rice husk has beenstudied by measuring carbonization ratio with different carbonization temperature and oxygenconcentration in furnace in charcoal burning process. Results show that carbonization ratiodecreases with the rising of carbonization temperature for a given oxygen concentration.Andcarbonization ratio decreases with the rising of oxygen concentration for a given carbonization t-emperature.The conductivity and volume shrinkage of bamboo charcoal increase with the risingof carbonization temperature for a given oxygen concentration. The conductivity of bamboocharcoal increases with the reducing of oxygen concentration for a given carbonization temperat-ure. Combined with scanning electron microscope, the internal structure for bamboo charcoal hasbeen observed and analyzed under different oxygen concentration. EDS analysis shows that thetrace elements of Mg, P are included in bamboo from Liyang Bamboo production areas.Due to the high carbonization ratio for rice husk, SiO2in rice husk char must be removed bydissolving, cooking and soaking in NaOH solution. So then rice husk char has been weighed fordifferent time respectively. Results show that SiO2in rice husk char could be removedcompletely by dissolving, cooking and soaking in NaOH solution for over20hours.To studythe pore size distribution of rice husk char after removing silicon, the paper got N2adsorption-desorption isotherms and pore size distribution analysis of the desorption curves byusing the specific surface area and porosity analyzer. By changing activation temperature ofrice husk char after removing silicon, the specific surface area and pore of rice husk char havebeen obtained and compared. Combined with images of scanning electron microscope, theproduction process of high specific surface area activated carbon has been studied.Results show that with400℃carbonization temperature, rice husk char is dissolved and cookedin NaOH solution for24hours, and finally activated at750℃for120minutes, and then you canget activated carbon with a high specific surface area of2075m2/g.